diff --git a/src/masking_general.jl b/src/masking_general.jl
index 4846d4a..789781f 100644
--- a/src/masking_general.jl
+++ b/src/masking_general.jl
@@ -36,7 +36,7 @@ function masking_co_occurrence(
 
         else
 
-            cube_out[i] .= cube_in_to_mask[i]
+            cube_out[i] = cube_in_to_mask[i]
 
         end